Small pit, largely infilled.

Very little of the original quarry survives today. Some traces of former buildings remain. An original access track at pit level survives, along with a later track that runs alongside the lake. Although water is present on site, there is no evidence that it was ever harnessed to power machinery during the quarry’s working life.

Castell Cidwm was a small hillside and pit quarry that was active mainly during the 1870s. At its peak, around 18 men worked the site, and a steam pump and winder were installed to support operations and manage water ingress. After this period of more intensive activity, occasional small-scale re-working continued intermittently at the quarry up to the 1970s. Access to the site was via a cart road that ran alongside Llyn Cwellyn